[F87source]

Originally Posted by Lady Jane

Speaking of regulations, I've been trying to educate myself regarding engine sizes over the decades.

From brutish V12 to tiny but sophisticated 1.6 liters.

https://en.wikipedia.org/wiki/Formula_One_engines

They're trying to match what is commonly seen on street cars to make f1 relevant. Hence the E10 fuel regulations because most of the world if I am not mistaken has some bio fuel mandate, in north america it happens to be E10 (unless you are buying from some specific brands - in Canada shell 91 and chevron 94 doesn't have ethanol).